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Why can't second-row elements have expanded octets?
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Second-row elements can't have expanded octets because they only have 2s and 2p sublevels, which can hold a maximum of 8 electrons.
What are the bond angles in the molecular geometry of trigonal planar structures like BH3?
The bond angles in trigonal planar structures are 120°.
What role do formal charges play in determining the most stable Lewis structure?
Formal charges help identify the most stable Lewis structure by minimizing the charges on each atom, distributing electrons to maximize stability.
What defines an incomplete octet, and give an example.
An incomplete octet occurs when an atom has fewer than eight electrons around it. For example, Boron in BH3 has only six electrons.
How does the odd number of electrons in NO affect its Lewis structure?
NO has 11 valence electrons. In its Lewis structure, one major resonance structure shows Nitrogen with 7 electrons and Oxygen with 8 to be more stable due to oxygen's higher electronegativity.
What is the molecular geometry of NO2 and its effect on bond angles?
NO2 has a bent molecular geometry due to the lone pair on nitrogen, resulting in bond angles of approximately 134°.
Draw the Lewis structure for BH3 and identify its molecular geometry.
Boron has 3 valence electrons and each Hydrogen has 1 valence electron, totaling 6 electrons. The structure is trigonal planar with 120° bond angles.
What is the octet rule?
The octet rule states that atoms should have eight electrons around them in their valence shell.
Compare the valence electron count and Lewis structure stability between NO and NO2.
NO has 11 valence electrons, often resulting in Nitrogen having 7 electrons. NO2 has 17 valence electrons, leading to incomplete octet structures and consideration of formal charges for stability.
What is the molecular geometry of ICl5 and how many valence electrons does it have?
ICl5 has a total of 42 valence electrons. The molecular geometry is square pyramidal with one lone pair on iodine.
Explain the Lewis structure for NO2 and the concept of formal charges in it.
NO2 has 17 valence electrons. Possible structures need to consider lone pairs and yield formal charges that are typically minimized, often resulting in an incomplete octet for Nitrogen.
What defines an expanded octet, and give an example.
An expanded octet refers to an atom having more than eight electrons in its valence shell. Phosphorus in PCl5, with ten electrons, is an example.
Why can third-row elements have expanded octets?
Third-row elements can have expanded octets because they have 3s, 3p, and 3d sublevels, allowing up to 18 electrons.
Describe the electron count and geometry for PCl5.
Phosphorus has 5 valence electrons, and each Chlorine has 7 valence electrons, totaling 40 valence electrons. Phosphorus has an expanded octet with 10 electrons, and the geometry is trigonal bipyramidal.
Identify a molecule with an odd number of valence electrons and describe its Lewis structure.
Nitric Oxide (NO) has an odd number of electrons (11). Its Lewis structure often shows Nitrogen with 7 electrons and Oxygen with 8, due to oxygen's higher electronegativity.
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